The overall objective of this research project is to determine the extent to which myocardial hypertrophy in man is a reversible process, and to identify the determinants of reversibility. In particular, we plan to answer the following questions: 1) Are the pattern of hypertrophy and the nature of the inciting stress important determinants of reversibility? 2) What is the relation between contractile performance and reversibility? 3) What is the relation between the altered compliance which may accompany hypertrophy and reversibility of that hypertrophy?